1 files changed, 148 insertions, 0 deletions
diff --git a/src/backenddb/pg_lookup_refunds.c b/src/backenddb/pg_lookup_refunds.c
new file mode 100644
index 00000000..2facb73f
--- /dev/null
+++ b/src/backenddb/pg_lookup_refunds.c
@@ -0,0 +1,148 @@
+/*
+   This file is part of TALER
+   Copyright (C) 2022 Taler Systems SA
+
+   TALER is free software; you can redistribute it and/or modify it under the
+   terms of the GNU General Public License as published by the Free Software
+   Foundation; either version 3, or (at your option) any later version.
+
+   TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along with
+   TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+/**
+ * @file backenddb/pg_lookup_refunds.c
+ * @brief Implementation of the lookup_refunds function for Postgres
+ * @author Iván Ávalos
+ */
+#include "platform.h"
+#include <taler/taler_error_codes.h>
+#include <taler/taler_dbevents.h>
+#include <taler/taler_pq_lib.h>
+#include "pg_lookup_refunds.h"
+#include "pg_helper.h"
+
+/**
+ * Closure for #lookup_refunds_cb().
+ */
+struct LookupRefundsContext
+{
+  /**
+   * Function to call for each refund.
+   */
+  TALER_MERCHANTDB_RefundCallback rc;
+
+  /**
+   * Closure for @e rc.
+   */
+  void *rc_cls;
+
+  /**
+   * Plugin context.
+   */
+  struct PostgresClosure *pg;
+
+  /**
+   * Transaction result.
+   */
+  enum GNUNET_DB_QueryStatus qs;
+};
+
+
+/**
+ * Function to be called with the results of a SELECT statement
+ * that has returned @a num_results results.
+ *
+ * @param cls of type `struct LookupRefundsContext *`
+ * @param result the postgres result
+ * @param num_results the number of results in @a result
+ */
+static void
+lookup_refunds_cb (void *cls,
+                   PGresult *result,
+                   unsigned int num_results)
+{
+  struct LookupRefundsContext *lrc = cls;
+
+  for (unsigned int i = 0; i<num_results; i++)
+  {
+    struct TALER_CoinSpendPublicKeyP coin_pub;
+    struct TALER_Amount refund_amount;
+    struct GNUNET_PQ_ResultSpec rs[] = {
+      GNUNET_PQ_result_spec_auto_from_type ("coin_pub",
+                                            &coin_pub),
+      TALER_PQ_result_spec_amount_with_currency ("refund_amount",
+                                                 &refund_amount),
+      GNUNET_PQ_result_spec_end
+    };
+
+    if (GNUNET_OK !=
+        GNUNET_PQ_extract_result (result,
+                                  rs,
+                                  i))
+    {
+      GNUNET_break (0);
+      lrc->qs = GNUNET_DB_STATUS_HARD_ERROR;
+      return;
+    }
+    lrc->rc (lrc->rc_cls,
+             &coin_pub,
+             &refund_amount);
+    GNUNET_PQ_cleanup_result (rs); /* technically useless here */
+  }
+  lrc->qs = num_results;
+}
+
+
+enum GNUNET_DB_QueryStatus
+TMH_PG_lookup_refunds (
+  void *cls,
+  const char *instance_id,
+  const struct TALER_PrivateContractHashP *h_contract_terms,
+  TALER_MERCHANTDB_RefundCallback rc,
+  void *rc_cls)
+{
+  struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_string (instance_id),
+    GNUNET_PQ_query_param_auto_from_type (h_contract_terms),
+    GNUNET_PQ_query_param_end
+  };
+  struct LookupRefundsContext lrc = {
+    .rc = rc,
+    .rc_cls = rc_cls,
+    .pg = pg
+  };
+  enum GNUNET_DB_QueryStatus qs;
+
+  /* no preflight check here, run in transaction by caller! */
+  TALER_LOG_DEBUG ("Looking for refund of h_contract_terms %s at `%s'\n",
+                   GNUNET_h2s (&h_contract_terms->hash),
+                   instance_id);
+  check_connection (pg);
+  PREPARE (pg,
+           "lookup_refunds",
+           "SELECT"
+           " coin_pub"
+           ",refund_amount"
+           " FROM merchant_refunds"
+           " WHERE order_serial="
+           "  (SELECT order_serial"
+           "     FROM merchant_contract_terms"
+           "    WHERE h_contract_terms=$2"
+           "      AND merchant_serial="
+           "        (SELECT merchant_serial"
+           "           FROM merchant_instances"
+           "          WHERE merchant_id=$1))");
+  qs = GNUNET_PQ_eval_prepared_multi_select (pg->conn,
+                                             "lookup_refunds",
+                                             params,
+                                             &lookup_refunds_cb,
+                                             &lrc);
+  if (0 >= qs)
+    return qs;
+  return lrc.qs;
+}